Thanks, both are listed as required for software updates, https://support.apple.com/en-us/101555 https://support.apple.com/en-us/101555 Is there a good non-App

Thanks, both are listed as required for software updates, https://support.apple.com/en-us/101555 https://support.apple.com/en-us/101555 Is there a good non-Apple reference for the functions performed by their servers?